Scores of different cheeses are manufactured by the cheese industry. The ingredients of the recipe typically include milk, microorganisms as a starter, rennet, and salt. The cheese flavor, texture and body often hinges upon the particular preferences of the cheese maker. A basic cheese recipe typically entails adding a starter culture (a microorganism) to the milk, allowing the milk to coagulate with or without rennet, and then draining off the whey with or without aging to develop cheese flavor, texture and body.
Cheese manufacture includes the acid curd cheeses typically made by coagulating milk with acid forming starters or cultures and the rennet curd cheeses made by coagulating milk with rennet. The starter favors lactic acid formation which coagulates the milk and hastens coagulation by the rennet. Rennet favors expulsion of whey and fusion of curd particles. In the cheese manufacture, the coagulating milk reaches a condition the cheese maker considers to be an optimum curding point, at which processing stage the cheese coagulum is often curded into small cubes by cutting with a meshed wire followed by draining the whey from the cheese vat to provide what is often referred to as cheese curds or a curded cheese product. The cheese curds are quite resilient and may be compressed or molded into the desired cheese bricks. Each cheese maker practices certain techniques, including when to curd, which contribute unique flavoring or textural character to the cheese.
Cheese making is an art. Cheese makers are skilled artisans who rely upon a host of objective and subjective recipe criteria designed to consistently replicate a cheese product of a well defined flavor, texture, body and consumer acceptability. Several hundred different kinds of cheese may be made from essentially the same ingredients simply by slightly varying the processing conditions. Each cheese maker, however, strives to consistently replicate a successful "in house" cheese recipe. Small recipe deviations can result in substantial departures from the desired end product. Sophisticated cheese consumers can often detect minor variations in flavor, texture, or body in a favorite cheese product. Cheese makers will often physically touch the cheese coagulum for purposes of ascertaining a proper curding stage.
An important decision in the cheese manufacture pertains to the optimum processing stage to cut or curd the cheese coagulum. Curding at what is considered to be an optimum curding point facilitates standardization in quality control and replication of the desired cheese end product. Failure to curd at the appropriate coagulation stage can lead to a cheese product substantially different in product identity from what was intended. Reproduction of the cheese recipe is essential to maintaining consumer acceptance and allegiance to any given cheese product.
There have been numerous attempts to instrumentally or analytically determine when a coagulum may be cut in a cheese manufacture. These attempts have not been entirely successful. Representative patents relying upon instruments to determine curding or cutting of coagulum in cheese making include U.S. Pat. Nos. 4,578,988; 4,611,928; 4,663,169; and 5,014,553. These patents collectively rely upon heating a thin metal wire with an electric current and monitoring the wire temperature for purposes of establishing a theoretical cutting point. These determinations rely upon extensive experimentation and correlation of accumulated data generated by a specific thin metal wire detector in a specific cheese coagulation and complex theoretical calculations and derivations derived from the accumulated data.
The use of a thin metal wire equipped with current feeding and voltage measuring terminals to determine the development of coagulum in a cheese making process is reportedly a complex and tedious task. The determination reportedly requires numerous plant runs to establish sufficient information for the calibration of the instrumentation and to compensate for inherent variations in the detected responses from the actual condition or actual state of the coagulum. Calibration of the equipment to the cheese making process requires tedious examination of the data and restructuring of the data in an attempt to establish what the calibrators consider to be optimum cheese curding time. If the "optimum cheese curding time" of the process calibrator fails to meet the cheese maker's desired cutting time, additional testing and data is generally required to recalibrate the cutting time.
There exists a need for a means to empirically determine by a cheese maker an optimum cheese curding stage in an automated curding in cheese manufacture. There exists a need for instrumentation which more precisely and accurately determines when a coagulating milk mass converts to a coagulated cheese product suitable for curding as empirically sought by the cheese maker. There exists a need for an accurate profile for tracking the thermal conductivity of a coagulating milk mass in a cheese manufacture which allows the cheese maker to determine precisely at what stage within the tracked profile the cutting of the cheese coagulum should occur.
It would be particularly beneficial to be able to record and store a composite profile of cheese coagulation processes in a conventional computer database and enable the cheese maker to select at that particular processing stage or juncture of the profile for curding the cheese coagulum. If these needs could be fulfilled, an ordinary worker would be able to replicate the empirical artfulness of a master cheese maker. Such a system would also allow the cheese industry to more consistently replicate the desired end product.